The Pediatric Gastroenterology Research Training Program described in this application offers a carefully organized opportunity for two or three years of research experience for four pediatricians or other post- doctoral scientists per year who are preparing for academic careers in Pediatric Gastroenterology and nutrition or in the developmental biology of the gastrointestinal tract and liver. The proposed program is based in the Division of Pediatric Gastroenterology and Nutrition at the New England Medical Center (NEMCH), collaborating departments at Tufts University School of Medicine (TUSM) and the Massachusetts Institute of Technology, and the NEMCH/TUSM NIH-Digestive Disease Core Center. This program has been highly productive in this setting since 1983 under the guidance of the Program Director, Richard J. Grand, M.D., and faculty preceptors from the Departments of Anatomy/Cell Biology, Biology, Medicine, Microbiology and Molecular Biology, Nutrition Pediatrics and Physiology. The program has attracted scientists with Ph.D. and M.D./Ph.D. degrees, although the majority of trainees are physicians with the M.D. degree. Approximately 15 applications are received and two new trainees enter the program annually; customarily pediatricians enter from clinical training not supported by this program, while other scientists enter from a variety of previous experiences at Tufts or other institutions. Recruitment of minority candidates is active. Research training is provided by investigators who are actively engaged in Research of relevance to developmental processes, including gene expression, receptor biology, intracellular targeting, pathogenic microbiology and nutritional biochemistry and metabolism. As a consequence of the multi-disciplinary nature of the collaborations achieved in this program and the proximity of the preceptors to each other, a rich environment for the training of young scientists is available. The program is integrated so that trainees are exposed to a broad range of research activities whole concentration on a specific area of investigation under the close scrutiny of a specific mentor. Research experience and progress are monitored during informal work-in- progress sessions, and formally at regular intervals by the training faculty; reports are communicated by the Program Director to each trainee. In addition to the trainees' specific research project, program enrichment is achieved through graduate-level course work, research seminars, journal clubs, a required course in scientific integrity, and an additional course in computer science, biostatistics, research methodology and medical journalism. Attention by the Program Director and preceptors to the individual needs of the trainees, strong guidance, and the breadth and depth of the scientific program assure that trainees acquire sufficient skills and research credentials so that, upon completion of training, they are prepared to take the role of independent investigators at Tufts or other institutions.